Systems and methods for identifying regions of interest in multiple imaging modalities

ABSTRACT

A method of identifying a location of a region of interest within a breast utilizes compressed location coordinates for the region of interest recorded while the breast is under compression during an x-ray imaging procedure such as mammography or tomosynthesis. The compressed location coordinates are converted to uncompressed location coordinates using a mathematical tissue deformation model. The volume and density of the breast affects how the coordinates are translated for use with an ultrasound imaging system. A system including a computing system in communication with an ultrasound imaging system is utilized to perform the method. The resultant predicted location coordinates of the region of interest are used to guide a healthcare provider to potential lesions that are to be examined using ultrasound, where the potential lesions had been previously identified during a screening mammogram.

This application is being filed on Mar. 23, 2021, as a PCT International Patent Application and claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 63/000,700, filed Mar. 27, 2020, the entire disclosure of which is incorporated by reference in its entirety.

BACKGROUND

Medical imaging provides a non-invasive method to visualize the internal structure of a patient. Visualization methods can be used to screen for and diagnose cancer in a patient. For example, early screening can detect lesions within a breast that might be cancerous so that treatment can take place at an early stage in the disease.

Mammography and tomosynthesis utilize x-ray radiation to visualize the breast in a compressed position. These techniques are often used to screen patients for potentially cancerous lesions. Traditional mammograms involve acquiring two-dimensional images of the breast from various angles. Tomosynthesis produces a plurality of x-ray images, each of discrete layers or slices of the breast, through the entire thickness thereof. Tomosynthesis pieces together a three-dimensional visualization of the breast. Mammography and tomosynthesis are typically performed while the patient is standing and the patient's breast tissue is under compression.

If a lesion is found, a diagnostic ultrasound may be the next step in determining whether the patient has a tumor. Ultrasound uses sound waves, typically produced by piezoelectric transducers, to image tissue in a patient. An ultrasound probe focuses the sound waves by producing an arc-shaped sound wave that travels into the body and is partially reflected from the layers between different tissues in the patient. The reflected sound wave is detected by the transducers and converted into electrical signals that can be processed by the ultrasound scanner to form an ultrasound image of the tissue. Ultrasound is typically performed while the patient is in a supine position and the patient's breast tissue is not under compression.

During diagnostic ultrasound imaging procedures, technologists and radiologists often have difficulty navigating to and locating a lesion previously identified during x-ray imaging. It is challenging to correlate the position of the lesion from x-ray imaging to ultrasound imaging because the former is performed while the patient is upright and the breast tissue is under compression while the latter is performed while the patient is lying down and the breast tissue is not under compression.

It is against this background that the present disclosure is made. Techniques and improvements are provided herein.

SUMMARY

Embodiments of the disclosure are directed to a method of identifying a location of a region of interest within a breast. An indication of the region of interest within the breast is received. Compressed location coordinates are received of the region of interest within the breast when the breast is under compression. A mathematical tissue deformation model is applied to the compressed location coordinates of the region of interest to predict uncompressed location coordinates of the region of interest within the breast when the breast is not under compression. The predicted uncompressed location coordinates are saved to a data store.

In another aspect, an ultrasound navigation system includes at least one data store; a processing device; and a memory storing instructions that, when executed by the processor, facilitate performance of operations. The operations include: accessing from the data store compressed location coordinates of a region of interest within a breast under compression; calculating, using a mathematical tissue deformation model, predicted uncompressed location coordinates of the region of interest within the breast when the breast is not under compression; and saving the predicted uncompressed location coordinates to the data store.

In yet another aspect, a non-transitory machine-readable storage medium stores executable instructions that, when executed by a processor, facilitate performance of operations. The operations include: recording an x-ray image of a breast; receiving an indication of a region of interest on the x-ray image of the breast; recording one or more architectural markers in or around the region of interest; determining compressed location coordinates of the region of interest within the breast when the breast is under compression; saving the compressed location coordinates and one or more architectural markers in a data store; applying a mathematical tissue deformation model to the compressed location coordinates of the region of interest to predict uncompressed location coordinates of the region of interest within the breast when the breast is not under compression; saving the predicted uncompressed location coordinates to a data store; communicating the predicted uncompressed location coordinates and architectural markers to an optical tracking system in communication with an ultrasound system; and displaying a coordinate model and the architectural markers on a display in communication with the ultrasound system.

The details of one or more techniques are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these techniques will be apparent from the description, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example system for locating a region of interest within a breast.

FIG. 2 illustrates a schematic diagram of an example system for managing healthcare data including imaging data.

FIG. 3 is a schematic view of an exemplary x-ray imaging system.

FIG. 4 is a perspective view of the x-ray imaging system of FIG. 3 .

FIG. 5 depicts the x-ray imaging system in a breast positioning state for left mediolateral oblique (LMLO) imaging orientation.

FIG. 6 depicts an example ultrasound imaging system.

FIG. 7 depicts an example of the ultrasound imaging system of FIG. 6 in use with a breast of a patient.

FIG. 8 is a flow diagram illustrating an example method of identifying a region of interest within a breast.

FIG. 9 illustrates an example display of the graphical user interface of FIG. 1 .

FIG. 10 is a schematic diagram of an exemplary computing system usable to implement one or more aspects of the present disclosure.

DETAILED DESCRIPTION

The present disclosure is directed to systems and methods for navigating to a region of interest within a breast using an imaging device. In particular, a computing system utilizes a tissue deformation model to calculate predicted coordinates of a region of interest within a breast. The region of interest may be identified during visualization of the breast using a first imaging modality such as mammography or tomosynthesis. In some instances, the region of interest may require further imaging to determine if a lesion within the region of interest is potentially cancerous. In such instances, an ultrasound imaging procedure may be performed on the breast.

Technicians and radiologists may find it difficult to locate the same region of interest due to the fact that the position of the breast is different in an ultrasound procedure as compared to an x-ray imaging procedure (e.g., mammography or tomosynthesis). Typically the patient is in an upright position with the breast under compression during x-ray imaging while the patient is typically in a supine position and the breast is not under compression during ultrasound. This shift in position can make it difficult to correlate lesions found in the x-ray image with an image produced by ultrasound. Technicians typically use different coordinate systems and other means to identify the location of a region of interest in a breast in ultrasound as compared to x-ray imaging.

The computing system operating a tissue deformation model can translate coordinates used during the x-ray imaging procedure to predicted coordinates usable during the ultrasound imaging procedure. The predicted coordinates can provide greater confidence to an ultrasound technician that he or she is viewing the same region of interest identified during an x-ray imaging procedure.

FIG. 1 illustrates an example system 100 for locating a region of interest within a breast. The system 100 includes a computing system 102, an x-ray imaging system 104, and an ultrasound imaging system 106. In some examples, the system 100 operates to guide a technician to a location of interest in a breast during ultrasound imaging based on data collected during an x-ray imaging procedure where the location of interest was first identified.

The computing system 102 operates to process and store information received from the x-ray imaging system 104 and provide processed information to the ultrasound imaging system 106. In the example of FIG. 1 , the computing system 102 includes a tissue deformation model 110 and a data store 112. In some examples, the tissue deformation model 110 and data store 112 are housed within the memory of the computing system 102. In some examples, the computing system 102 accesses the tissue deformation model 110 and data store 112 from a remote server such as a cloud computing environment.

The tissue deformation model 110 is utilized to analyze information obtained about a region of interest in a breast during x-ray imaging and convert that information into location identifying information usable to navigate to the same region of interest during ultrasound imaging. Coordinates of the region of interest determined during an x-ray imaging procedure while the breast tissue is under compression are converted into a different set of coordinates that are used to locate the region of interest during ultrasound imaging of the breast tissue not under compression.

The tissue deformation model 110 predicts the ultrasound coordinates based on the density and volume of the breast being imaged. In some examples, the tissue deformation model 110 is based on a deformation curve determined based on the amount of spread of the breast tissue this is recorded on a mammography paddle. With the known compression force of the paddle and the density determined by the x-ray, the tissue deformation model 110 is calculated for each patient.

The data store 112 operates to store information received from the x-ray imaging system 104 and information after it is processed by the tissue deformation model. In some examples, the data store 112 is actually two or more separate data stores. For example, one data store could be a remote data store that stores compressed location coordinates for regions of interest from one or more x-ray imaging systems. Another data store could be housed locally within the computing system 102 and store the predicted uncompressed location coordinates of regions of interest. In some examples, the data store 112 could be part of an electronic medical record (EMR) system.

The x-ray imaging system 104 operates to take images of breast tissue using x-ray radiation. The x-ray imaging system 104 includes an x-ray imaging device 114 and an x-ray computing device 116 in communication with the x-ray imaging device 114. The x-ray imaging device 114 is described in further detail in relation to FIGS. 3-5 . The x-ray computing device 116 operates to receive inputs from a healthcare provider H to operate the x-ray imaging device 114 and view images received from the x-ray imaging device 114.

The ultrasound imaging system 106 operates to take images of breast tissue using ultrasonic sound waves. The ultrasound imaging system 106 is described in further detail in relation to FIGS. 6-7 . The ultrasound imaging system 106 includes an ultrasound computing device 118 and an ultrasound imaging device 120. The ultrasound computing device 118 operates to receive inputs from a healthcare provider H to operate the ultrasound imaging device 120 and view images received from the ultrasound imaging device 120.

FIG. 1 illustrates how information obtained from an x-ray imaging system 104 could be utilized by an ultrasound imaging system 106. A healthcare provider H operates the x-ray computing device 116 to capture x-ray images of the breast of a patient P using the x-ray imaging device 114. The x-ray image may be taken as part of a routine health screening or a follow up diagnostic screening. The images are reviewed by a radiologist who may identify one or more regions of interest in the patient P's breast that require additional analysis to determine if lesions within those regions of interest are potentially cancerous and require a biopsy. The radiologist may mark the regions of interest and a computing system (102 or another system) may determine the coordinates based on the selection by the radiologist and may store the coordinates in a DICOM format associated with the x-ray image. In another example, the coordinates may be stored associated with the patient by patient ID. In some examples, the coordinates are stored in a database with a unique identifier linked to a patient's electronic medical record accession number.

In one example, coordinates for the regions of interest may be determined using a computer aided detection system stored at computing device 116 and communicated to the computing system 102. In some examples, the computer aided detection system utilizes artificial intelligence or machine learning techniques to determine the coordinates. The coordinates recorded either by the radiologist or by the computing device 116 are analyzed using the tissue deformation model 110. The output of the analysis is a set of predicted coordinates that can be communicated to the ultrasound computing device 118 to be used typically at a subsequent appointment, often in a location different than that where the imaging procedure was performed.

A healthcare provider H operating the ultrasound computing device 118 uses the predicted coordinates to navigate to the region of interest on the patient P's breast using the ultrasound imaging device 120. In some examples, the predicted coordinates of the ROI are used in conjunction with a pictorial representation of a breast on a display of the ultrasound computing device 118. The predicted coordinates are used to generate a visual indicator on an image of a breast of the location of the region of interest. In some examples, this is represented such that the ROI is shown as a clock position relative to a nipple of the pictorial representation of the breast. Additionally, a different visual indicator can be displayed to show a current location of an ultrasound probe. In some examples, a dot can be used to indicate the ROI location while a rectangle indicates the location of the ultrasound probe. In some examples, the orientation of the probe can be indicated with the rectangle and is updated in real time. When the ultrasound probe is positioned over the region of interest, the visual indicators are shown to converge on a display of the ultrasound computing device 118. This visual guide makes it much easier for a healthcare professional to confirm that the same lesion identified by the x-ray imaging system 104 is being examined with the ultrasound imaging system 106. One example of such a display is provided in FIG. 10 .

FIG. 2 illustrates a schematic diagram of an example system 150 for managing healthcare data including imaging data. The system 150 includes multiple computing components in communication with one another through a communication network 152. The computing components can include a tracking system 154, a navigation system 156, an EMR system 158, and a display system 160 in addition to the computing system 102, x-ray imaging system 104, and ultrasound imaging system 106 described in FIG. 1 .

It should be noted that, although the ‘systems’ are shown in FIG. 1 as functional blocks, different systems may be integrated into a common device, and the communication link may be coupled between fewer than all of the systems; for example, the tracking system 154, navigation system 156 and display system 160 may be included in an acquisition work station or a technologist work station which may control the acquisition of the images in a radiology suite. Alternatively, the navigation system 156 and tracking system 154 may be integrated into the ultrasound imaging system 106, or provided as standalone modules with separate communication links to the display 160, x-ray imaging system 104 and ultrasound system 106. Similarly, skilled persons will additionally appreciate that communication network 152 can be a local area network, wide area network, wireless network, internet, intranet, or other similar communication network.

In one example, the x-ray imaging system 104 is a tomosynthesis acquisition system which captures a set of projection images of a patient's breast as an x-ray tube scans across a path over the breast. The set of projection images is subsequently reconstructed to a three-dimensional volume which may be viewed as slices or slabs along any plane. The three-dimensional volume may be stored locally at the x-ray imaging system 104 (either on the x-ray imaging device 114 or on the x-ray computing device 116) or at a data store such as the data store 112 in communication with the x-ray imaging system 104 through the communication network 152. In some examples, the three-dimensional volume could be stored in a patient's file within an electronic medical record (EMR) system 158. Additional details regarding an example x-ray imaging system are described in reference to FIGS. 3-5 .

The x-ray imaging system 104 may transmit the three-dimensional x-ray image volume to a navigation system 156 via the communication network 152, where such x-ray image can be stored and viewed. The navigation system 156 displays the x-ray image obtained by the x-ray imaging system. Once reconstructed for display on navigation system 156, the x-ray image can be reformatted and repositioned to view the image at any plane and any slice position or orientation. In some examples, the navigation system 156 displays multiple frames or windows on the same screen showing alternative positions or orientations of the x-ray-image slice.

Skilled persons will understand that the x-ray image volume obtained by x-ray imaging system 104 can be transmitted to navigation system 156 at any point in time and is not necessarily transmitted immediately after obtaining the x-ray image volume, but instead can be transmitted on the request of navigation system 156. In alternative examples, the x-ray image volume is transmitted to navigation system 156 by a transportable media device, such as a flash drive, CD-ROM, DVD-ROM diskette, or other such transportable media device.

The ultrasound imaging system 106 obtains an ultrasound image of a tissue of a patient, typically using an ultrasound probe, which is used to image a portion of a tissue of a patient within the field of view of the ultrasound probe. For instance, the ultrasound imaging system 106 may be used to image a breast, and more specifically, the ducts of a breast. Ultrasound imaging system 106 obtains and displays an ultrasound image of a patient's anatomy within the field of view of the ultrasound probe and typically displays the image in real-time as the patient is being imaged. In some examples, the ultrasound image can additionally be stored on a storage medium, such as a hard drive, CD-ROM, flash drive or diskette, for reconstruction or playback at a later time. Additional details regarding the ultrasound imaging system are described in reference to FIGS. 6-7 .

In some examples, the navigation system 156 can access the ultrasound image, and in such examples the ultrasound imaging system 106 is further connected to the communication network 152 and a copy of the ultrasound image obtained by the ultrasound imaging system 106 can be transmitted to the navigation system 156 via communication network 152. In other examples, the navigation system 156 can remotely access and copy the ultrasound image via the communication network 152. In alternative examples, a copy of the ultrasound image can be stored on the data store 112 or EMR system 158 in communication with the navigation system 156 via the communication network 152 and accessed remotely by the navigation system 156.

The tracking system 154 is in communication with the navigation system 156 via the communications network 152 and may track the physical position in which the ultrasound imaging system 106 is imaging the tissue of the patient. In some examples, the tracking system 154 can be connected directly to the navigation system 156 via a direct communication link or wireless communication link. The tracking system 154 tracks the position of transmitters connected to ultrasound imaging system 106 and provides the navigation system 156 with data representing their coordinates in a tracker coordinate space. In some examples, the tracking system 154 may be an optical tracking system comprising an optical camera and optical transmitters, however skilled persons will understand that any device or system capable of tracking the position of an object in space can be used. For example, skilled persons will understand that in some examples an RF tracking system can be used, comprising an RF receiver and RF transmitters.

The ultrasound imaging system 106 may be configured for use with the navigation system 156 by a calibration process using the tracking system 154. Transmitters that are connected to the ultrasound probe of ultrasound imaging system 106 may transmit their position to tracking system 154 in the tracker coordinate space, which in turn provides this information to navigation system 156. For example, transmitters may be positioned on the probe of the ultrasound imaging system 106 so that the tracking system 154 can monitor the position and orientation of the ultrasound probe and provide this information to the navigation system 156 in the tracker coordinate space. The navigation system 156 may use this tracked position to determine the position and orientation of the ultrasound probe, relative to the tracked position of the transmitters.

In some examples, configuration occurs using a configuration tool. In such examples, the position and orientation of the configuration tool may be additionally tracked by tracking system 154. During configuration the configuration tool contacts the transducer face of the ultrasound probe of ultrasound imaging system 106 and tracking system 154 transmits information representing the position and orientation of the configuration tool in the tracker coordinate space to navigation system 156. Navigation system 156 may determine a configuration matrix that can be used to determine the position and orientation of the field of view of the ultrasound probe in the tracker coordinate space, based on the tracked position of the transmitters connected to the ultrasound probe. In alternative examples, a database having configuration data of a plurality of brands or models of various ultrasound probes can be used to pre-load a field of view configuration into navigation system 156 during configuration.

Once the ultrasound imaging system 106 is configured with the navigation system 156, the tissue of a patient can be imaged with ultrasound imaging system 106. During ultrasound imaging, the tracking system 154 monitors the position and orientation of the ultrasound probe of the ultrasound imaging system 106 and provides this information in the tracker coordinate space to the navigation system 156. Since the ultrasound imaging system 106 has been configured for use with the navigation system 156, the navigation system 156 is able to determine position and orientation of the field of view of the ultrasound probe of the ultrasound imaging system 106.

The navigation system 156 can be configured to co-register an ultrasound image with an x-ray image. In some examples, the navigation system 156 can be configured to transform the position and orientation of the field of view of the ultrasound probe from the tracker coordinate space to a position and orientation in the x-ray image, for example, to x-ray system coordinates. This can be accomplished by tracking the position and orientation of the ultrasound probe and transmitting this positional information in the tracker coordinate space to navigation system 156 and relating this positional information to the x-ray coordinate system.

For example, a user can select an anatomical plane within the x-ray image, and the user can then manipulate the position and orientation of a tracked ultrasound probe to align the field of view of the ultrasound probe with the selected anatomical plane. Once alignment is achieved, the associated tracker space coordinates of the ultrasound image can be captured. Registration of the anatomic axes (superior-inferior (SI), left-right (LR) and anterior-posterior (AP)) between the x-ray image and the tracker coordinate space can be determined from the relative rotational differences between the tracked ultrasound field of view orientation and the selected anatomical plane using techniques known to those of skill in the art.

This configuration may further include the selection of landmarks within the x-ray image, for example, using an interface permitting a user to select an anatomical target. In some examples, the landmark can be an internal tissue landmark, such as veins or arteries, and in other examples, the landmark can be an external landmark, such as a fiducial skin marker or external landmark, such as a nipple. The same landmark selected in the x-ray image can be located with the ultrasound probe, and upon location, a mechanism can be provided for capturing coordinates of the representation of the target in the tracker coordinate space. The relative differences between the coordinates of the target in the x-ray image and the coordinates of the target in the tracker coordinate space are used to determine the translational parameters required to align the two co-ordinate spaces. The plane orientation information acquired previously can be combined with the translation parameters to provide a complete 4×4 transformation matrix capable of co-registering the two coordinate spaces.

The navigation system 156 can then use the transformation matrix to reformat the x-ray image being displayed so that the slice of tissue being displayed is in the same plane and in the same orientation as the field of view of the ultrasound probe of the ultrasound imaging system 106. Matched ultrasound and x-ray images may then be displayed side by side, or directly overlaid in a single image viewing frame. In some examples, the navigation system 156 can display additional x-ray images in separate frames or positions on a display screen. For example, the x-ray image can be displayed with a graphical representation of the field of view of the ultrasound imaging system 106 wherein the graphical representation of the field of view is shown slicing through a 3D representation of the x-ray image. In other examples annotations can be additionally displayed, these annotations representing, for example, the position of instruments imaged by the ultrasound imaging system 106, such as biopsy needles, guidance wires, imaging probes or other similar devices.

In other examples, the ultrasound image being displayed by the ultrasound imaging system 106 can be superimposed on the slice of the x-ray image being displayed by the navigation system 156 so that a user can view both the x-ray and ultrasound images simultaneously, overlaid on the same display. In some examples, the navigation system 156 can enhance certain aspects of the super imposed ultrasound or x-ray images to increase the quality of the resulting combined image.

As described in FIG. 1 , the computing system 102 operates to predict uncompressed location coordinates for a region of interest using a tissue deformation model 110. The predicted uncompressed location coordinates can be used by the navigation system 156 to aid a user in finding the region of interest while operating the ultrasound imaging system 106.

The electronic medical record system 158 stores a plurality of electronic medical records (EMRs). Each EMR contains the medical and treatment history of a patient. Examples of electronic medical records systems 158 include those developed and managed by Epic Systems Corporation, Cerner Corporation, Allscripts, and Medical Information Technology, Inc. (Meditech).

FIG. 3 is a schematic view of an exemplary x-ray imaging system 104. FIG. 4 is a perspective view of the imaging system 104. Referring concurrently to FIGS. 3 and 4 , the x-ray imaging system 104 immobilizes a patient's breast 202 for x-ray imaging (either or both of mammography and tomosynthesis) via a breast compression immobilizer unit 204 that includes a static breast support platform 206 and a moveable compression paddle 208. The breast support platform 206 and the compression paddle 208 each have a compression surface 210 and 212, respectively, that move towards each other to compress and immobilize the breast 202. In known systems, the compression surface 210, 212 is exposed so as to directly contact the breast 202. The platform 206 also houses an image receptor 216 and, optionally, a tilting mechanism 218, and optionally an anti-scatter grid. The immobilizer unit 204 is in a path of an imaging beam 220 emanating from x-ray source 222, such that the beam 220 impinges on the image receptor 216.

The immobilizer unit 204 is supported on a first support arm 224 and the x-ray source 222 is supported on a second support arm 226. For mammography, support arms 224 and 226 can rotate as a unit about an axis 228 between different imaging orientations such as CC and MLO, so that the system 104 can take a mammogram projection image at each orientation. In operation, the image receptor 216 remains in place relative to the platform 206 while an image is taken. The immobilizer unit 204 releases the breast 202 for movement of arms 224, 226 to a different imaging orientation. For tomosynthesis, the support arm 224 stays in place, with the breast 202 immobilized and remaining in place, while at least the second support arm 226 rotates the x-ray source 222 relative to the immobilizer unit 204 and the compressed breast 202 about the axis 228. The system 104 takes plural tomosynthesis projection images of the breast 202 at respective angles of the beam 220 relative to the breast 202.

Concurrently and optionally, the image receptor 216 may be tilted relative to the breast support platform 206 and in sync with the rotation of the second support arm 226. The tilting can be through the same angle as the rotation of the x-ray source 222, but may also be through a different angle selected such that the beam 220 remains substantially in the same position on the image receptor 216 for each of the plural images. The tilting can be about an axis 230, which can but need not be in the image plane of the image receptor 216. The tilting mechanism 218 that is coupled to the image receptor 216 can drive the image receptor 216 in a tilting motion.

For tomosynthesis imaging and/or CT imaging, the breast support platform 206 can be horizontal or can be at an angle to the horizontal, e.g., at an orientation similar to that for conventional MLO imaging in mammography. The x-ray imaging system 104 can be solely a mammography system, a CT system, or solely a tomosynthesis system, or a “combo” system that can perform multiple forms of imaging. An example of such a combo system has been offered by the assignee hereof under the trade name Selenia Dimensions.

When the system is operated, the image receptor 216 produces imaging information in response to illumination by the imaging beam 220, and supplies it to an image processor 232 for processing and generating breast x-ray images. A system control and work station unit 238 including software controls the operation of the system and interacts with the operator to receive commands and deliver information including processed-ray images.

FIG. 5 depicts an exemplary x-ray imaging system 104 in a breast positioning state for left mediolateral oblique MLO (LMLO) imaging orientation. A tube head 258 of the system 104 is set in an orientation so as to be generally parallel to a gantry 256 of the system 104, or otherwise not normal to the flat portion of a support arm 260 against which the breast is placed. In this position, the technologist may more easily position the breast without having to duck or crouch below the tube head 258.

The x-ray imaging system 104 includes a floor mount or base 254 for supporting the x-ray imaging system 104 on a floor. The gantry 256 extends upwards from the floor mount 252 and rotatably supports both the tube head 258 and a support arm 260. The tube head 258 and support arm 260 are configured to rotate discretely from each other and may also be raised and lowered along a face 262 of the gantry so as to accommodate patients of different heights. An x-ray source, described elsewhere herein and not shown here, is disposed within the tube head 258. The support arm 260 includes a support platform 264 that includes therein an x-ray receptor and other components (not shown). A compression arm 266 extends from the support arm 260 and is configured to raise and lower linearly (relative to the support arm 260) a compression paddle 268 for compression of a patient breast during imaging procedures. Together, the tube head 258 and support arm 260 may be referred to as a C-arm.

A number of interfaces and display screens are disposed on the x-ray imaging system 104. These include a foot display screen 270, a gantry interface 272, a support arm interface 274, and a compression arm interface 276. In general the various interfaces 272, 274, and 276 may include one or more tactile buttons, knobs, switches, as well as one or more display screens, including capacitive touch screens with graphic user interfaces (GUIs) so as to enable user interaction with and control of the x-ray imaging system 104. In examples, the interfaces 272, 274, 276 may include control functionality that may also be available on a system control and work station, such as the x-ray computing device 116 of FIG. 1 . Any individual interface 272, 274, 276 may include functionality available on other interfaces 272, 274, 276, either continually or selectively, based at least in part on predetermined settings, user preferences, or operational requirements. In general, and as described below, the foot display screen 270 is primarily a display screen, though a capacitive touch screen might be utilized if required or desired.

In examples, the gantry interface 272 may enable functionality such as: selection of the imaging orientation, display of patient information, adjustment of the support arm elevation or support arm angles (tilt or rotation), safety features, etc. In examples, the support arm interface 274 may enable functionality such as adjustment of the support arm elevation or support arm angles (tilt or rotation), adjustment of the compression arm elevation, safety features, etc. In examples, the compression arm interface 276 may enable functionality such as adjustment of the compression arm elevation, safety features, etc. Further, one or more displays associated with the compression arm interface 276 may display more detailed information such as compression arm force applied, imaging orientation selected, patient information, support arm elevation or angle settings, etc. The foot display screen 270 may also display information such as displayed by the display(s) of the compression arm interface 276, or additional or different information, as required or desired for a particular application.

In general, the various interfaces and display screens disposed on the x-ray imaging system 104 may be used by a technologist during various imaging procedures performed on a patient. The technologies described herein improve efficiency of workflow which may be advantageous for a number of reasons. For example, efficient workflow can reduce the amount of time of an imaging procedure. This helps reduce the stress for the patient and allows the technologist to see a greater number of patients in a given time frame. Technologist performance may also be improved by utilizing the technologies described herein. That is, the technologist may be able to work more comfortably and avoid unnecessary or excessive bending, twisting, or straining during imaging procedures as the technologist works to position the patient and control the imaging system during imaging procedures. This can help reduce repetitive stress to the technologist, as well as reduce fatigue.

FIG. 6 depicts an example of an ultrasound imaging system 106. The ultrasound imaging system 106 includes an ultrasound probe 302 that includes an ultrasonic transducer 304. The ultrasonic transducer 304 is configured to emit an array of ultrasonic sound waves 306. The ultrasonic transducer 304 converts an electrical signal into ultrasonic sound waves 306. The ultrasonic transducer 304 may also be configured to detect ultrasonic sound waves, such as ultrasonic sound waves that have been reflected from internal portions of a patient, such as ducts within a breast. In some examples, the ultrasonic transducer 304 may incorporate a capacitive transducer and/or a piezoelectric transducer, as well as other suitable transducing technology.

The ultrasonic transducer 304 is also operatively connected (e.g., wired or wirelessly) to a display 310. The display 310 may be a part of a computing system, such as the ultrasound computing device 118 of FIG. 2 , which includes processors and memory configured to produce and analyze ultrasound images. The display 310 is configured to display ultrasound images based on an ultrasound imaging of a patient.

The ultrasound imaging performed in the ultrasound imaging system 106 is primarily B-mode imaging, which results in a two-dimensional ultrasound image of a cross-section of a portion of the interior of a patient. The brightness of the pixels in the resultant image generally corresponds to amplitude or strength of the reflected ultrasound waves.

Other ultrasound imaging modes may also be utilized. For example, the ultrasound probe may operate in a 3D ultrasound mode that acquires ultrasound image data from a plurality of angles relative to the breast to build a 3D model of the breast.

In some examples, ultrasound images may not be displayed during the acquisition process. Rather, the ultrasound data is acquired and a 3D model of the breast is generated without B-mode images being displayed.

The ultrasound probe 302 may also include a probe localization transceiver 308. The probe localization transceiver 308 is a transceiver that emits a signal providing localization information for the ultrasound probe 302. The probe localization transceiver 308 may include a radio frequency identification (RFID) chip or device for sending and receiving information as well as accelerometers, gyroscopic devices, or other sensors that are able to provide orientation information. For instance, the signal emitted by the probe localization transceiver 308 may be processed to determine the orientation or location of the ultrasound probe 302. The orientation and location of the ultrasound probe 302 may be determined or provided in three-dimensional components, such as Cartesian coordinates or spherical coordinates. The orientation and location of the ultrasound probe 302 may also be determined or provided relative to other items, such as an incision instrument, a marker, a magnetic direction, a normal to gravity, etc. With the orientation and location of the ultrasound probe 302, additional information can be generated and provided to the surgeon to assist in guiding the surgeon to a lesion within the patient, as described further below. While the term transceiver is used herein, the term is intended to cover both transmitters, receivers, and transceivers, along with any combination thereof.

FIG. 7 depicts an example of the ultrasound imaging system 106 in use with a breast 312 of a patient. The ultrasound probe 302 is in contact with a portion of the breast 312. In the position depicted in FIG. 7 , the ultrasound probe 302 is being used to image a duct 314 of the breast 312. To image the duct 314, the ultrasonic transducer 304 emits an array of ultrasonic sound waves 306 into the interior of the breast 312. A portion of the ultrasonic sound waves 306 are reflected off internal components of the breast, such as the duct 314 when the duct is in the field of view, and return to the ultrasound probe 302 as reflected ultrasonic sound waves 316. The reflected ultrasonic sound waves 316 may be detected by the ultrasonic transducer 304. For instance, the ultrasonic transducer 304 receives the reflected ultrasonic sound waves 316 and converts the reflected ultrasonic sound waves 316 into an electric signal that can be processed and analyzed to generate ultrasound image data on display 310.

The depth of the duct 314 or other objects in an imaging plane may be determined from the time between a pulse of ultrasonic waves 306 being emitted from the ultrasound prove 302 and the reflected ultrasonic waves 316 being detected by the ultrasonic probe 302. For instance, the speed of sound is well-known and the effects of the speed of sound based on soft tissue are also determinable. Accordingly, based on the time of flight of the ultrasonic waves 306 (more specifically, half the time of flight), the depth of the object within an ultrasound image may be determined. Other corrections or methods for determining object depth, such as compensating for refraction and variant speed of waves through tissue, may also be implemented. Those having skill in the art will understand further details of depth measurements in medical ultrasound imaging technology. Such depth measurements and determinations may be used to build a 3D model of the breast 312, and more specifically, a 3D model of the ducts 314 of the breast 312.

In addition, multiple frequencies or modes of ultrasound techniques may be utilized. For instance, real time and concurrent transmit and receive multiplexing of localization frequencies as well as imaging frequencies and capture frequencies may be implemented. Utilization of these capabilities provide information to co-register or fuse multiple data sets from the ultrasound techniques to allow for visualization of ducts 164 and other medical images on the display 310. The imaging frequencies and capture sequences may include B-mode imaging (with or without compounding), Doppler modes (e.g., color, duplex), harmonic mode, shearwave and other elastography modes, and contrast-enhanced ultrasound, among other imaging modes and techniques.

Referring now to FIG. 8 , an example method 500 of identifying a location of a region of interest within a breast is described. In some examples, the systems and devices described in FIGS. 1-7 are usable to implement the method 500. In particular, the computing system 102 of FIGS. 1-2 operates to implement the steps of the method 500 to aid a healthcare provider in navigating to a region of interest within a breast during an imaging procedure.

At operation 502, an x-ray image of a breast is recorded. In some examples, the x-ray imaging device 114 of the x-ray imaging system 104 of FIGS. 1-2 operates to record the x-ray image as the result of inputs provided by a healthcare provider H at an x-ray computing device 116. In some examples, the x-ray image is acquired using digital breast tomosynthesis. In some examples, the x-ray image could be obtained from a remote data store. In such examples, the x-ray image may be have recorded at a different time and place and then stored in an EMR or other data store.

At operation 503, a deformation curve is determined for the breast. While the x-ray image is being obtained during a mammogram, the breast is compressed with a paddle with a known amount of force. Marks on the paddle indicate a distance and the distance that the breast tissue spreads under compression is recorded. The known force with the distance are used to determine a deformation curve that approximates the volume and density of the breast.

At operation 504, an indication of a region of interest on the x-ray image is received. In some examples, the indication is received from the healthcare provider H. In some examples, the healthcare provider H may be a radiologist located at a different location from the x-ray imaging system 104. The healthcare provider H may operate a computing device to display a user interface that allows the healthcare provider H to easily interact with x-ray images to highlight a region of interest by means of inputs provided with an input device in communication with the x-ray computing device 116 such as a mouse, a touchscreen, or a stylus. The region of interest may include one or more lesions identified by the healthcare provider H that require additional analysis. In other examples, the indication is received from a computer aided detection system that determines regions of interest using computer algorithms.

At operation 506, architectural marks are recorded in and around the region of interest. In some examples, this step is optional. However, in some instances it may be helpful to record architectural marks or biomarkers to aid in navigating to the region of interest in future imaging procedures. Such biomarkers can include naturally occurring marks (e.g. ducts, scar tissue, etc.) or artificial marks (e.g. biopsy implant marker, features of a breast implant, etc.). The architectural marks, biomarkers, or landmarks are recorded while the breast is under compression.

At operation 508, compressed location coordinates of the region of interest are determined. Coordinates of the region of interest are recorded during the x-ray imaging process using the x-ray imaging system 104. In some examples, the uncompressed location coordinates include at least two of a clock position relative to the nipple, a depth from the surface of the breast, and a distance from the nipple. Having all three coordinates improves the accuracy of the location coordinates. In some examples, the coordinates can be Cartesian coordinates or polar coordinates. In some examples, a region of interest may be identified within a particular slice within a tomosynthesis image stack (z coordinate) and its position can be further identified by x and y coordinates within that image slice.

At operation 509, a tissue deformation model is generated for the breast based on the x-ray image and deformation curve. The volume and density of the breast is used to calculate the tissue deformation model. In some examples, machine learning techniques are used to calculate the tissue deformation model based on large data sets of information about breast tissue.

At operation 510, the compressed location coordinates, architectural markers (if recorded), and tissue deformation model are saved to a data store. In some examples, this information is saved to the data store 112 of FIG. 1 . In other examples, the information could be saved to a patient's medical record within an EMR system 158. In some examples, the compressed location coordinates as well as any recorded architectural markers or biomarkers are communicated directly to a tracking system in communication with an ultrasound system.

At operation 512, the mathematical tissue deformation model is applied to the compressed location coordinates to predict uncompressed location coordinates of the region of interest. The tissue deformation model predicts uncompressed location coordinates based on the volume and density of the breast tissue.

At operation 514, the predicted uncompressed location coordinates are saved to a data store. In some examples, the data store can be the data store 112 of FIGS. 1-2 . In other examples, the uncompressed location coordinates could be saved to a patient's EMR. The uncompressed location coordinates are typically saved in a format that is easily used by a navigation system 156 in conjunction with an ultrasound imaging system 106.

At operation 516, the predicted uncompressed location coordinates and architectural markers (if available) are communicated to an optical tracking system in communication with an ultrasound imaging system. In some examples the optical tracking system is the tracking system 154 of FIG. 2 which is in communication with the ultrasound imaging system 106 through the communication network 152. Additional details about the operation of the optical tracking system 154 are provided above in reference to FIG. 2 .

At operation 518, a coordinate model and the architectural markers (if available) are displayed on a display in communication with the ultrasound imaging system 106. The display could be part of an ultrasound computing device 118 in communication with an ultrasound imaging device 120 as shown in FIG. 1 . In some examples, the coordinate model, architectural markers, and the x-ray images are displayed on an ultrasound computing device 118 in communication with the ultrasound imaging device 120. This display helps to guide a healthcare provider to the region of interest.

FIG. 9 shows an example of the GUI 130 of FIG. 1 . In some examples, the GUI 130 is displayed on a computing device such as the ultrasound computing device 118 of FIG. 1 . In the example of FIG. 9 , the GUI 130 displays an x-ray image 602 and an ultrasound image 604 of a breast 202 side-by-side. A target lesion 606 previously identified during x-ray imaging is indicated in the x-ray image 602 with a visual marker. The corresponding ultrasound image 604 of the breast 202 shows an indication of a potential lesion 608. A confidence level indicator 610 is displayed providing the likelihood that the target lesion 606 and potential lesion 608 are a match as a percentage. In this example, there is a 99.9% match.

The GUI 130 also includes a diagram 612 indicating the location on the breast 202 where the ultrasound image 604 is being taken. This diagram 612 includes a marker 620 for the ROI location as well as an indicator 618 of the current location of the ultrasound probe. Additionally, coordinates 614 are displayed. In this example, the coordinates 614 indicate the location of a potential lesion in the right breast at the 11:00 clock position, 2 cm from the nipple.

FIG. 8 is a block diagram illustrating an example of the physical components of a computing device 400. The computing device 400 could be any computing device utilized in conjunction with the system 100 for locating a region of interest within a breast such as the x-ray computing device 116 or ultrasound computing device 118 of FIG. 1 .

In the example shown in FIG. 8 , the computing device 400 includes at least one central processing unit (“CPU”) 402, a system memory 408, and a system bus 422 that couples the system memory 408 to the CPU 402. The system memory 408 includes a random access memory (“RAM”) 410 and a read-only memory (“ROM”) 412. A basic input/output system that contains the basic routines that help to transfer information between elements within the computing device 400, such as during startup, is stored in the ROM 412. The computing system 400 further includes a mass storage device 414. The mass storage device 414 is able to store software instructions and data.

The mass storage device 414 is connected to the CPU 402 through a mass storage controller (not shown) connected to the system bus 422. The mass storage device 414 and its associated computer-readable storage media provide non-volatile, non-transitory data storage for the computing device 400. Although the description of computer-readable storage media contained herein refers to a mass storage device, such as a hard disk or solid state disk, it should be appreciated by those skilled in the art that computer-readable data storage media can include any available tangible, physical device or article of manufacture from which the CPU 402 can read data and/or instructions. In certain examples, the computer-readable storage media includes entirely non-transitory media.

Computer-readable storage media include volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer-readable software instructions, data structures, program modules or other data. Example types of computer-readable data storage media include, but are not limited to, RAM, ROM, EPROM, EEPROM, flash memory or other solid state memory technology, CD-ROMs, digital versatile discs (“DVDs”), other optical storage media, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by the computing device 400.

According to some examples, the computing device 400 can operate in a networked environment using logical connections to remote network devices through a network 152, such as a wireless network, the Internet, or another type of network. The computing device 400 may connect to the network 152 through a network interface unit 404 connected to the system bus 422. It should be appreciated that the network interface unit 404 may also be utilized to connect to other types of networks and remote computing systems. The computing device 400 also includes an input/output controller 406 for receiving and processing input from a number of other devices, including a touch user interface display screen, or another type of input device. Similarly, the input/output controller 406 may provide output to a touch user interface display screen or other type of output device.

As mentioned briefly above, the mass storage device 414 and the RAM 410 of the computing device 400 can store software instructions and data. The software instructions include an operating system 418 suitable for controlling the operation of the computing device 400. The mass storage device 414 and/or the RAM 410 also store software instructions, that when executed by the CPU 402, cause the computing device 400 to provide the functionality discussed in this document.

Although various embodiments and examples are described herein, those of ordinary skill in the art will understand that many modifications may be made thereto within the scope of the present disclosure. Accordingly, it is not intended that the scope of the disclosure in any way be limited by the examples provided. 

What is claimed is:
 1. A method of identifying a location of a region of interest within a breast, the method comprising: receiving, at a computing device associated with an x-ray imaging device, an indication of the region of interest within the breast; obtaining compressed location coordinates of the region of interest within the breast when the breast is under compression; applying a mathematical tissue deformation model to the compressed location coordinates of the region of interest to predict uncompressed location coordinates of the region of interest within the breast when the breast is not under compression; and saving the predicted uncompressed location coordinates to a data store.
 2. The method of claim 1, wherein the region of interest is identified during an x-ray imaging procedure of the breast when the breast is under compression.
 3. The method of claim 1, wherein the uncompressed location coordinates comprise at least two of a clock position relative to a nipple of the breast, a depth from a surface of the breast, and a distance from the nipple.
 4. The method of claim 1, wherein the compressed location coordinates comprise at least one of Cartesian coordinates and polar coordinates.
 5. The method of claim 1, further comprising reporting the predicted uncompressed location coordinates of the region of interest to an optical tracking system in communication with an ultrasound system.
 6. The method of claim 2, wherein the x-ray imaging procedure is digital breast tomosynthesis.
 7. The method of claim 1, wherein obtaining the compressed location coordinates comprises accessing the compressed location coordinates from a remote data store.
 8. The method of claim 2, wherein receiving the indication of the region of interest within the breast comprises receiving input indicating a lesion identified during the x-ray imaging procedure.
 9. The method of claim 1, wherein the mathematical tissue deformation model calculates the predicted uncompressed location coordinates based on a density and volume of the breast, and wherein the mathematical tissue deformation model is generated based on a deformation curve and x-ray image of the breast.
 10. The method of claim 5, further comprising reporting a location of at least one biomarker to the optical tracking system, the biomarker being obtained during an x-ray imaging procedure of the breast when the breast is under compression.
 11. An ultrasound navigation system comprising: at least one data store; a processing device; and a memory storing instructions that, when executed by the processor, facilitate performance of operations, comprising: accessing from the data store compressed location coordinates of a region of interest within a breast under compression; calculating, using a mathematical tissue deformation model, predicted uncompressed location coordinates of the region of interest within the breast when the breast is not under compression; and saving the predicted uncompressed location coordinates to the data store.
 12. The system of claim 11, wherein the operations further comprise reporting the predicted uncompressed location coordinates of the region of interest to an optical tracking system in communication with an ultrasound system.
 13. The system of claim 12, wherein the operations further comprise reporting a location of at least one biomarker from the data store to the optical tracking system.
 14. The system of claim 11, wherein the region of interest is identified during an x-ray imaging procedure of the breast when the breast is under compression.
 15. The system of claim 14, further comprising determining a distance the breast spreads on a paddle during the x-ray imaging procedure and determining a deformation curve based on the distance and a known force applied to the breast with the paddle.
 16. The system of claim 13, wherein the at least one biomarker is identified during an x-ray imaging procedure of the breast when the breast is under compression.
 17. The system of claim 11 wherein the compressed location coordinates comprise at least one of Cartesian coordinates and polar coordinates.
 18. The system of claim 11, wherein the uncompressed location coordinates comprise at least two of a clock position relative to a nipple of the breast, a depth from a surface of the breast, and a distance from the nipple.
 19. A non-transitory machine-readable storage medium, comprising executable instructions that, when executed by a processor, facilitate performance of operations, comprising: recording an x-ray image of a breast; receiving an indication of a region of interest on the x-ray image of the breast; recording one or more architectural markers in or around the region of interest; determining compressed location coordinates of the region of interest within the breast when the breast is under compression; saving the compressed location coordinates and one or more architectural markers in a data store; applying a mathematical tissue deformation model to the compressed location coordinates of the region of interest to predict uncompressed location coordinates of the region of interest within the breast when the breast is not under compression; saving the predicted uncompressed location coordinates to a data store; communicating the predicted uncompressed location coordinates and architectural markers to an optical tracking system in communication with an ultrasound system; and displaying a coordinate model and the architectural markers on a display in communication with the ultrasound system.
 20. The non-transitory machine-readable storage medium of claim 19, wherein the mathematical tissue deformation model calculates the predicted uncompressed location coordinates based on a density and volume of the breast. 